Dimer Projection Method DIPRO for xtb (#856)

* Incorporate the Dimer Projection Method for xTB (DIPRO)
---------

Signed-off-by: MtoLStoN <70513124+MtoLStoN@users.noreply.github.com>
Co-authored-by: MtoLStoN <70513124+MtoLStoN@users.noreply.github.com>

man/xtb.1.adoc

@@ -222,6 +222,10 @@ NOTE: You can only select *one* runtyp, only the first runtyp will be used
 *--modef* 'INT'::
     modefollowing algorithm. 'INT' specifies the mode that should be
     used for the modefollowing.
+
+*--dipro* ['REAL']:: 
+    the dimer projection method for the calculation of electronic coupling integrals between two fragments.
+    'REAL' sets the threshold for nearly degenerate orbitals to still be considered (default = 0.1 eV).
 
 
 GENERAL

src/CMakeLists.txt

@@ -17,6 +17,7 @@
 
 add_subdirectory("api")
 add_subdirectory("coulomb")
+add_subdirectory("dipro")
 add_subdirectory("disp")
 add_subdirectory("docking")
 add_subdirectory("extern")
@@ -58,6 +59,7 @@ list(APPEND srcs
   "${dir}/define.f90"
   "${dir}/detrotra.f90"
   "${dir}/dipole.f90"
+  "${dir}/dipro.F90"
   "${dir}/drsp.f"
   "${dir}/dtrafo.f90"
   "${dir}/dynamic.f90"